Core bit



March 30,1943. w, B NCBLE Em, 2,314,947

I'CORE BIT Filed Nov. 23, 1940 2 Sheets-Sheet l BJVoHe.

ENTOR I the cutter-assembly and of joining this Patented Mar. 30, 1943 comm Wiley n. Noble and John E. Holloss, Houston,

. Tex, *asslgnors to Reed Roller Bit Company,

Houston, Tex, a corporation of Texas Application November as, 1940, Serial No. stem Claims.

This invention relates to core bits for use in taking samples of earth formation as ahole is being drilled. It has for'its general object the provision of such a device whlchwill be simpler and less expensive to manufacture and yet will have all of the desirable qualities of similar devices of the prior art.

Another object of this invention is .to'provide a corecutter assembly which will be extremely strong and rugged and which may be attached to or removed from the bit head in any field shop.

Other objects and advantages of this invention will become apparent from the following description taken in connection with theaccompanying drawings wherein is set forth by way of illustrat'ion and example one embodiment of this inven-.

tion.

In the drawings:

Fig. 1 shows a longitudinal cross section through a bit head constructed in accordance with this invention.

Fig. 2 is a transverse cross section taken along the line of 2-2 of Fig. 1.

Fig. 3 is a side elevation of one of the segments which carries one of the outside cutter bearings and forms a part of the structure shown in Fig. 1. Fig. 4 is a top plan view of the structure shown in Fig.. 3. a a

Fig. 5 is a fragmentary cross section along the longitudinal plane represented by the line H of Fig. 2.

Fig. 6 is a fragmentary side elevation showing the manner of joining together the segments of to the body of the bit by welding- Fig. 7 is an exploded view showing the various assembly parts in longitudinal cross section but omittins the cutters.

Referring first to Fig.1; the'bit head I is threaded to the lower end of the outer barrel I and carries on. its lower end the cutter assembly constructed in accordance with this invention.

As shown, the device is ,depicted as drilling.

through a formation 3 and forming a core 4, which is passing upwardly into the inner core barrel 5. Carried within the bit head I and within the lower end of the inner .core barrel I is a core catcher consisting ofa catcher body 0 and pivoted dogs 1 adapted to dig into and break of! the core when the bit is elevated with respect to the core. The bit head is provided with slush passageways 8 adapted to conduct slush from. the annular space 8 between the inner and outer barrels down through the bit head and cause it to impinge upon the respective inner'and outer cutters l0 and II.

The cutter assembly,-which carries the cutters II and II, is composed of the cutters themselves, the inside cutter bearing ring ii, the outside cutter bearing segments II, and the inside cutter mounted on thebit head tby merely placing it over the bit head and welding around the upper the use of a cutting torch to destroy the welded "unit.

bearing supportlngsegments .4. The ring I! is adapted toseat against a shoulder li formed in the lower end of the bit head but is not secured to that shoulder nor is it secured to the bit head inany way except through the segments l8 and H, as will be presently described. 1 s

The ring I 2' is p'rovidedat alternate points about its circumference withintegral downwardly and outwardly extending bearing shafts I! for the inside cutters Ill andwi'th openings ll adapted to receive the inner ends of the bearing shafts I8, which carry. the outside cutters "ll. The bearingshafts l8 extend downwardly and inwardly and are made integral with the seg: ments ii. The segments l4 areprovided with openings l9 forthe reception of theouter ends of the bearing shafts ll. Itwill be appreciated that the number of the segments ll will corre- 'spond to the number of the inside cutter bearing shafts l6 and thatfthere will be a like number of the segments l3 alternating with thesegments a .H. The segments ll and It together are of such an extent as to take up substantially'the entire circumference of the completed structure.

In practice, the inside cutters Ill will'fl rst be assembled on the bearing shafts l5 and the segments l4 will be put in plac'e on the outer-ends of those shafts and secured thereto temporarily in some suitable manner as by tack welding. I

The outside cutters ll will then be placed on the bearing shafts ll of the respectivesegrnents l3 and these segments with the cutters thereon will be assembled with respect to the ring l2, so that"v theinslde ends of the'shafts II project into the holes ll where they will likewise be secured temporarily as by tack welding. The entire cutter assembly thus provided is completed by joining the segments together along their edges by welding as shown at and by weldingthe outer and inner ends of the shafts I and 18 respectively in the respective openings providedtherefor, as shown at II and 22. 1

The cutter assembly thus provided maybe ends of the segments as shown at 23. This is all that is necessary to join this cutter assembly-to the bit head- When the cutter assembly becomes worn or it becomes for any reason desirable to replace it, it can be removedmerelyby joint 23 and 'whe'n'this welded joint is destroyed the entire cutter assembly may be removed as 'a Itwill be seen from has been provided whereby all the objects and advantages sought by this invention may be achieved. I It isi'urther apparent that with the g device described, it is possible to remove a cutter;

assembly from a bit head of a core bit such as the foregoing, that means that to which this invention relates, and to replace the same with a new assembly in the field by the use of no special tools other than the usual welding and cutting equipment to be found in the field. It will be appreciated that the cut ters will not be disturbed in their relation to each other either during the removal of or during the attachment of the cutter assembly to the bit head. necessary inside of the bit head or cutterassembly during the attachment or removal of the same and that no skill or precise measurements are required except, for the usual welding'skill and practice. L t

Having described our invention, we claim:

- 1. A core bit comprising a cora -barrel, a tubular bithead threadedly mounted on the lower end of said barrel, said bit head having portions on the inner and outer surfaces thereof at its lower end cut away to provide annular shoulders on said surfaces, a plurality of axially extending slush passageways in the bit head intermediate said inner and outer surfaces having discharge openings at the lower end of the bit head, an annular cutter assembly having spaced'upwardly extending inner and outer annular members seated on's'aid inner and outer shoulders respectively with said outer annular member detachably connected to said bit head by a weld, and roller cutters mounted between said inner and outer annularmembers' and adapted to be positioned beneath the slush passageway discharge openings atjthe lower end of the bit head.

2. A core bit comprising acore barrel, 9. tubu lar bithead thread'edly mounted on the lower end of said barrel, said bit head having portions on the 'inn'er and outer surfacesthereof at its lower end cut away to provide annular shoulders on saidf'surfaces, a plurality of axially extending slush passageways in the bit head intermediate It is further apparent that no welding is a seated on said inner and outer shoulders respectively with said outer annular member detachably connected to said bit head by a weld, said inner annular member having a plurality of circumferentially spaced cutter shaft receiving openings, a cutter shaft carried by the inner annular member between adjacent openings and extending outwardly from the circumference of the inner annular member, said outer annular member having a plurality of circumferentially spaced openings therein for receiving the outer ried bythe outer annular member between adjalar bit head threadedly mounted on the lower end said inner and outer surfaces having discharge openings at the lower end of the bit head, an

annular cutter assembly having spaced upwardly extending inner and outer annular members seated on saidjinner'and outer shoulders respectively withsaid outer annular member detachably connected to said bit head by a weld, said inner annular member having a plurality of circumferentially spaced cutter shaft receiving openings, a cutter shaft carried by the inner annular member between'adjacent openings and extending outwardly from the circumference of the inner annular member, said outer annular member comprising a plurality of welded segments, those of the segments facing the openings in the inner annular member having cutter shafts extending therefrom and entering said openings and those of said segments facing the shafts carried by the inner member having openings there,- in to receive the ends of the shafts carried by said inner members, and means connecting the free ends of said shafts in the openings into which they extend, and roller cutterston said shafts.

3. A core bit comprising a core barrel, a tubular bit head threadedly mounted on the lower end of said barrel, said bit head having portions on the inner and outer surfaces thereof at its lower end cut, away to provideannular shoulders on said surfaces, a plurality of axially extending slush passageways in the bit head intermediate J said inner and outer surfaces having discharge openings at the lower end of the bit head, an annularcutter assembly having spaced upwardly of saidbarrel, said bit head having portions on the inner and outer surfaces thereof at its lower end cut away to provide annular shoulders on said surfaces, a plurality of axially extending slush passageways in the bit head intermediate said inner and outer surfaces having discharge openings at the lower end of the bit head, an annular cutter assembly having spaced upwardly extending inner and outer annular members seated on said inner and outer shoulders respectively with said outer annular member detaehably connected to said bit head by a weld, said inner annular member having a plurality of circumferentially spaced cutter shaft receiving openings, a cutter shaft carried by-the inner annular member between adjacent openings and extending outwardly from the circumference of the inner annular member, said outer annular member having a plurality of circumferentially spaced openings therein for-receiving the outer ends of the cutter shafts extending outwardly from the therein and extending inwardly and entering the openings in the inner annular member, the ends extending inner and outer annular members of theshafts carried by one member being conheated in the openings of the. other member, welds connecting the ends of the shafts of one member to the openings in the other member, and roller cutterson said shafts.

v 5; A core bit comprising a core barrel, a tubular bit head threadedlymounted on the lower end of said barrel, said bit head having a portion on the inner-surface thereof at its lower end cut away to provide an annular shoulder on said surface, a plurality of axially extending slush passageways in the bit head intermediate its inner and outer'surfaces having discharge openings at the lower end of the bit head, an annular cutter assembly having spaced upwardly extending inner and outer annular members with the inner member seated on said inner shoulder and with the upper portion of the outer annular member of said-cutter assembly connected to the lowerouter portion of said bit head by a weld, and roller cutters mounted between said inner ,and outer annular members and adapted to be positioned beneath the slush passageway discharge openings atthe lower end of the bit head, whereby said cutter assembly can be removed without disturbing said slush passageways.

- WILEY B. Noam Jorm a HOFFOBS. 

